Update OAuth2TokenMetadata.TOKEN_METADATA_BASE

Issue spring-projectsgh-137

Author: jgrandja

oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/token/OAuth2TokenMetadata.java

@@ -34,7 +34,7 @@
  */
 public class OAuth2TokenMetadata implements Serializable {
 	private static final long serialVersionUID = Version.SERIAL_VERSION_UID;
-	protected static final String TOKEN_METADATA_BASE = "token.metadata.";
+	protected static final String TOKEN_METADATA_BASE = "metadata.token.";
 
 	/**
 	 * The name of the metadata that indicates if the token has been invalidated.